Mitosis & Meiosis – Test Study Guide Key
Cell Cycle
1. From where do new cells arise?
All cells come from other cells.
2. Why does the body constantly make new cells?
Cells get too large for efficient diffusion of substances across the cell’s interior.
For unicellular reproduction - ex. fission
The larger the cell becomes, the more demands the cell places on its DNA.
For the growth of multi-cellular organisms. (ex. Fertilized egg divides and
becomes a multi-cellular organism)
4. Why must each new cell get a complete copy of the original cell’s DNA?
Cells need a complete set of DNA to function properly – it is the instruction
manual for the cell.
5. Copying DNA is known as replication.
6. The original cell that divides is called the mother cell, while the two, new identical cells
are called daughter cells.
Chromosomes
7. How many chromosomes are in a human body cell? 46
8. What makes up each chromosome?
DNA tightly coiled into two sister chromatids connected by the centromere.
910. Uncoiled chromosomes are called chromatin.
12. What are duplicated (doubled) chromosomes called? Homologous pairs
13. What holds chromatids together? Centromere
14. Sketch & label all parts of sister chromatids.
16. Where are autosomes found on a pairs? Pairs 1- 22
17. Where are sex chromosomes found on a pair? The 23rd pair
18. What is the genotype for males? XY For females? XX
19. The presence of which chromosome determines the sex of the child? Y
Cell Reproduction
20. What is asexual reproduction? Making new cells by making exact copies of the mother
cell. Only one parent.
22. What is sexual reproduction and give an example?
The formation of offspring by the combination of haploid cells from the
mother and father. Requires two parents. Ex. Pollination of a flower.
23. Which process produces identical new cells --- mitosis, meiosis, or both?
Mitosis
Cell Cycle
27. Name the 5 phases of the cell cycle.
Interphase, Prophase, Metaphase, Anaphase, Telophase
28. What is the longest phase of the cell cycle? Interphase the shortest phase? G2 of
interphase
29. Which phase has 3 stages & name them?
Interphase -- First Growth (G1), Synthesis (S), Second Growth (G2)
30. Which phase has 4 stages & name them?
Mitotic Phase – Prophase, Metaphase, Anaphase, Telophase
33. How do the new copies of DNA compare to the original DNA? Exact copies
36. Can the nucleus and nucleolus be seen during interphase? Yes
Mitosis
38. What part of a cell actually divides during mitosis? Nucleus
39. In which type of cell does mitosis occur --- prokaryote or eukaryote? Explain why.
Eukaryotes – because prokaryotes do not have a nucleus to divide.
41. Name, in order, the four stages of mitosis.
Prophase, Metaphase, Anaphase, Telophase
43. What happens to the nucleus & nucleolus during prophase? They disappear
45. What finishes forming by the end of Late Prophase? Spindle
46. Where are the poles of a cell? The two ends of the spindle the equator of a cell? The
middle
48. What happens to chromosomes during metaphase? They line up along the equator
49. During metaphase, where do chromosomes line up & what MOVES them there? Along
the equator – the centrioles and spindle fibers.
50. What happens to sister chromatids during anaphase? They are pulled apart
51. What pulls sister chromatids apart during anaphase? The spindle fibers and centrioles
52. Where are chromatids located during telophase? At opposite poles of the cell.
54. What reforms around each set of sister chromatids during telophase? Nuclear membrane
55. What organelle reappears inside the nucleus? Nucleolus
56. During telophase as the chromosomes uncoil, they reappear as chromatin.
57. What process or phase follows telophase? cytokinesis
58. What divides during cytokinesis? The cytoplasm and its contents
59. Explain how cytokinesis occurs in plants. A cell plate forms between the two new cells.
60. Explain how cytokinesis occurs in animals. A cleavage furrow forms to pinch the
membrane into two cells
61. How does the chromosome number of the parent cell compare to that of the 2 daughter
cells? How do the 3 cells compare in size? They are the same, both have 46. The two new
daughter cells are much smaller than the original mother cell.
62. If the parent cell has a chromosome number of 2n = 6, what will be the chromosome
number of the daughter cells? 6
63. Label these mitosis diagrams.
64. Label these stages.
Telophase
Anaphase
Interphase
Metaphase
Prophase
65. Eukaryotic cell division is used for diploid and haploid division of cells.
66. Parent cells before division are diploid or 2n = 46 chromosome number. What will be
the chromosome number of the two new cells? 46
67. Name these actual stages of cell division.
2 – Interphase
5 – Prophase
6 – Metaphase
9 – Anaphase
10 – Telophase
TEST YOURSELF ON MITOSIS
68. Identify these stages.
A & B – Interphase
C & D – Prophase
E – Metaphase
F – G – H – Anaphase
I – Telophase
69. Locate the four mitotic stages.
70. Eukaryotic cells before and after mitosis are diploid or 2n.
71. What happens if mitosis is NOT controlled? Cancer
Meiosis
72. Do chromosomes replicate or double before meiosis? Double
73. How many divisions occur in meiosis? Is this the same as mitosis? Explain. There are 2
divisions. This is different than mitosis because mitosis only has 1.
74. The original cell that divides by meiosis is diploid or 2n.
75. How many daughter cells can be produced by meiosis? Is this the same as mitosis?
Explain. 4 very different haploid daughter cells are formed. This is different than mitosis
which produces only 2 diploid cells identical to the parent cells.
76. What is the chromosome number of the daughter cells produced by meiosis? How does
this compare to the number of chromosomes in the original cell? n or haploid. Original
cell was 2n or diploid.
77. What are the daughter cells called that are produced by meiosis? Name them.
Gametes – Eggs and Sperm
78. Name the 2 types of meiosis.
a. Meoisis I
b. Meiosis II
79. In humans, how many chromosomes are in the original cells that undergoes meiosis?
Are they single or double stranded? 46 double stranded chromosomes
80. After one division, how many chromosomes are in the cells? Are they single or double
stranded? 23 double stranded chromosomes
81. After the second division, how many chromosomes are in the cells? Are they double or
single stranded? 23 single stranded chromosomes
82. Is meiosis sexual or asexual reproduction? sexual
83. Are eggs & sperm haploid or diploid? haploid
84. What process joins the egg & sperm to restore the original chromosome number of the
organism? Sexual reproduction or fertilization
85. When a sperm fertilizes an egg, a new 2n cell forms called the zygote.
86. Homologous chromosomes are pairs of sister chromatids that have the same genes, but
may have different alleles.
87. Meiosis reduces the chromosome number by half, while fertilization restores it.
88. In Meiosis I, what separates? Whole chromosomes
89. In Meiosis II, what separates? Chromatids
90. Name these stages of Meiosis I.
Interphase I Prophase I Metaphase I Anaphase I Telophase I
91. Name 2 things that occur in Prophase I.
Nuclear membrane disappears, centrioles move to opposite poles
93. What is a tetrad? Label the centromere and put a box around a sister chromatid.
A tetrad is a pair of homologous chromosomes that have lined up together.
Centromere
95. Crossing-over results in genetic variation in the offspring.
96. What happens during Metaphase I?
In metaphase I one, the pairs of homologous chromosomes line up at the equator.
97. Name 2 things that occur in Anaphase I?
In anaphase I, the spindle fibers pull the homologous chromosomes apart, while sister
chromatids stay together.
98. Name 3 things that occur in Telophase I?
In telophase I, the chromosomes will de-condense back into chromatin. The nuclear
membrane will reform. Cytokinesis will take place.
101. The gametes at the end of Meiosis II will have how many copies of a gene for a trait?
Their will be only one copy of a gene.
102. Name the stages in Meiosis II.
Prophase II, Metaphase II, Anaphase II, Telophase II
103. What happens in Prophase II?
Centrioles will again move to opposite poles, the spindle will reform. Nuclear membrane
will disappear,
104. Where are the sister chromatids in Metaphase II? Lined up at the equator
105. What happens to the sister chromatids during Anaphase II? They are pulled to
opposite poles
106. Name 4 things that occur in Telophase II? In telophase II, the chromatids will decondense back into chromatin. The nuclear membranes will reform. The cleavage furrow
will form. Cytokinesis will take place, forming four haploid daughter cells.
107. Meiosis results in 4 haploid cells called gametes that have one copy of each
chromosome and each allele for each gene in different .
Gametogenesis
108. Gametogenesis that produces sperm cells is called spermatogenesis.
109. Gametogenesis that produces egg cells is called oogenesis.
110. How many haploid cells after oogenesis will become an egg cell? Only one.
111. What happens to the polar bodies & WHY? Because egg cells require more energy,
one egg gets most of the cytoplasm and the other 3 haploid cells -- called polar bodies-wither and die.
Comparing Mitosis & Meiosis
112. Complete the following table comparing mitosis & meiosis.
Mitosis
Meiosis
Number of Divisions
One
Two
Number of Daughter Cells
Two
Four
Genetically Identical
Yes
No
Chromosome Number
46
23
Where Occurs
Somatic (Body) Cells
Sex Cells
Role
Make more identical cells to Make haploid sex cells with
replace dying cells, and
variations in genetic
allow growth of organism
makeup to take place in
sexual reproduction.
Disorders
113. What causes Down’s Syndrome? An extra copy of chromosome #21. (47 total)
114. What causes Turner’s Syndrome? Missing one X chromosome (45 total)
115. What does trisomy mean? Having three copies of a chromosome instead of two.
120. What is your name? HAHA – Just checking if you are awake after all these
questions. : )